Exam 1 - Chapter 1 - Epithelium Flashcards
What are the four basic types of tissue?
Epithelial
Connective
Nervous
muscle
What are the 3 general functions of epithelium?
Absorption
secretion
Providing living barrier
What are three specialized functions of epithelium?
Transport molecules across epithelium
Prevent transport of materials across epithelium (selective permeability)
Sensory (ex: taste buds, retina in eye).
What are 5 basic characteristics that epithelium share?
Cells are adjacent to each other.
Associated with complete or partial basement membrane.
Avascular
Associated with vascular connective tissue.
Cells held together by cells junctions.
What are the two parts of a complete basement membrane?
Basal lamina and
Reticular lamina
A partial basement membrane has only a ___?
Basal lamina
What are four functions of a basement membrane?
Provides a surface for epithelial attachment.
Molecular filter.
Limits stretch - protective.
Directs migration of cells (i.e. during wound healing.)
If epithelium is avascular, how do cells obtain nutrition?
By diffusion
What are the functions of connective tissue in association with epithelium?
Provide nutrition
Source of defensive cells
Cell junction that involves the sharing of intrinsic membrane proteins BETWEEN adjacent cells.
zonula occludens
What are two functions of zonula occludens?
Provides strong attachment.
Prevents the passage of materials between cells.
What are the linkage proteins between cells in zonula adherens cell junctions?
cadherins
What attaches the cytoskeleton to the cell membrane in zonula adherens?
Marginal bands (microfilaments)
What two regions are part of the zonula adherens?
Cadherins and marginal bands (microfilaments)
What are the two functions of zonula adherens cell junctions?
Strong attachment
Provide cell structural stability
What is another name for zonula occludens?
Tight junctions
What is another name for macula adherens?
desmosome
What is the function of macula adherens?
Provides strong attachment
Type of junction that is a disc shaped structure at the surface of one cell that are matched with identical structure at an adjacent cell surface.
Macula adherens (desmosome)
This type of cell junctions has connexins (proteins) arranged in a cylinder.
Gap junction
How many connexins in a gap junction are arranged in a cylinder?
six
A _______ = one complete structure in a gap junction.
connexon
The size of the openings in a gap junction can be controlled by what?
By the cell
What are the two functions of the gap junction?
Strong attachment
Allows direct transfer of small molecules and ions from one cell to another.
Junctional complex = 3 junctions in the following order beginning with the free cell surface:
Zona occludens
Zona adherens
Macula adherens
What are junctions that hold the epithelium to the basement membrane and the connective tissue below?
hemidesmosomes and
Focal point contacts
Help to connect epithelial to basal lamina.
hemidesmosome
Interim binds to structural CT glycoprotein and also connects to cytoskeleton.
Focal point contacts
What is a transmembrane protein of the cell membrane called?
integrin
An autoimmune skin disease causing large blistering lesions that burst, but do heal. (Usually fatal)
Bullous Pemphigoid
The cause of this disease is that antibodies bind to some proteins in hemidesmosomes.
Bullous pemphigoid
An autoimmune skin disease causing skin blistering that do not heal easily; excessive bleeding likely. Can be fatal.
Pemphigus Vulgaris
Cause of this disease is antibodies bind to some parts of desmosomes.
Pemphigus Vulgaris
Acute bacterial infection of the small intestines.
cholera
Cause of this disease: toxins disrupt proteins in zonula occludens with permits the loss of water and electrolytes from the CT below the epithelium.
cholera
Epithelium that is a single cell thick is called?
Simple epithelium
Functions of simple squamous epithelium.
Living filter
Provide barrier
Example locations of simple squamous epithelium (3)
Lung,
parietal layer of the Bowman’s capsule in the kidney,
serosa on the outside of organs
Functions of simple cuboidal epithelium.
Absorption
secretion
Provide a barrier
A single layer of cube shaped cells.
Simple cuboidal epithelium
Example locations for simple cuboidal epithelium.
exocrine ducts,
Thyroid follicular cells,
Kidney tubules
What is different about the nucleus of simple cuboidal epithelium?
Nucleus occupies much of the cell cytoplasm.
A single layer of cells that have height.
Simple columnar epithelium
Three functions of simple columnar epithelium.
Absorption
secretion
Provide a barrier
What is polarization in simple columnar?
Nucleus is all at same level, usually at bottom toward BM, all doing same fxn and more active at the bottom.
What is another name for ciliated psuedostratified columnar epithelium?
Respiratory epithelium
What are example locations for respiratory epithelium?
Trachea,
Respiratory region of nasal cavity
bronchii
This epithelium has three cell types of various heights and can have the appearance of stratified epithelium.
Respiratory epithelium
Aka ciliated psuedostratified columnar epithelium
What are the three types of cells in respiratory epithelium?
Goblet cells
ciliated columnar cells
Basal cells
What is the function of a goblet cell?
To produce mucus
What are ciliated columnar cells?
Columnar cells that contain Celia.
Cilia are anchored in the ______ of the cell.
apex
Celia are anchored in the apex of the cell by what?
Basal bodies
What is the function of the ciliated columnar cells?
To move mucus over the surface.
Short pyramidal cells in respiratory epithelium that do not reach the surface.
Basal cells
What is the function of basal cells in respiratory epithelium?
To be the stem cell for this type of epithelium (can divide and change into another cell type)
What are four types of surface specializations?
microvilli
stereocilia
Celia
glycocalyx
Finger-like projections at the apical surface on some epithelial cells.
microvilli
What are two other names for microvilli?
Brush border
Striated border
What is the function of microvilli?
To increase surface area so as to increase absorption.
What are some example locations of microvilli?
Kidney tubule cells
Small intestines
Extremely long microvilli, usually fewer present than in microvilli.
stereocilia
Are steriocilia related to true cilia?
NO
What is the function of stereocilia?
To increase surface area
What are example locations of stereocilia?
epididymis,
Cochlear hair cells
Thin apical hair-like extensions of the cytoskeleton.
cilia
What is the function of cilia?
To move something over a surface.
What are some example locations for cilia?
Trachea,
oviduct
Cells with cilia have many ____?
mitochondria
In cells with cilia, basal bodies block free surfaces so there is NO _____ or _____?
Absorption
secretion
Surface layer of glycoprotein and carbohydrates that covers some epithelium.
glycocalyx
Glycocalyx is produced by what?
Epithelial cells
What is the function of glycocalyx?
Protection
Cell recognition
What are some other possible functions of glycocalyx?
Cell adhesion
Hold enzymes
What are example locations of glycocalyx?
Stomach and small intestines
